More by hunger than by a wet diaper
Red and White blood cells:
These are produced by the stem cells in the bone marrow. There are two types of stem cells for producing white blood cells - Myeloid stem cells (producing phagocytes such as neutrophils and monocytes - the undeveloped version of macrophages) and Lymphoid stem cells (responsible for production of lymphocytes such as B and T cells).
Answer:
D
Explanation:
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Answer:
A myosin head bound to actin
Explanation:
Cross bridge cycling explains the sliding filament theory according to which thin and thick filament slide against each other for muscle contraction. The two myosin heads extend form the thick filament. One myosin head has binding site for ATP and other head has binding site for actin from thin filament.
When myosin head binds to actin a cross bridge is formed. When ATP binds to the other head the bridge dissociates. Actin binding site is free and myosin tries to bind with other actin during which ATP is hydrolysed into ADP and Pi. Myosin along with the ADP and free Pi successfully binds to another actin molecule. The cross bridge formed generates a powerful force and ADP and Pi are displaced from it. The cross bridge is now free again for binding of next ATP molecule and the cycle continues.
This is an example of passive immunity. Immunity to a disease is achieved through the presence of antibodies to that disease in a person's system. For example measles antibody will protect a person who is exposed to measles disease, but will have no effect if they are exposed to another disease. There are two types of immunity, namely; passive and active' Active immunity results when exposure to a disease triggers the immune system to produce antibodies to that disease. Passive immunity is provided when a person is given antibodies to a disease rather than producing them through his or her own immune system.